Lock Bumping 101: What it is, How it Works and How to Prevent it

It’s estimated that about two out of every three home invasions show no sign of forced entry. While this statistic is alarming enough, what’s perhaps more alarming is that your home or business could soon very well be included in this depending on what type of lock you outfit it with. That’s because if your home or office door is secured with a conventional cylinder or pin tumbler lock, there’s a good chance that it could be very easily opened by a thief via a common burglary technique known as “lock bumping.”

What is Lock Bumping?

As we told you in the opening, lock bumping is a very common burglary technique used on cylinder and/or pin tumbler locks. Specifically, the technique takes advantage of the mass production of these types of locks, enabling the access of deadbolts and standard key locks with what’s called a “bump key” or a “999/rapping key.” These types of keys can be made very affordably and feature a plethora of cuts and valleys to fit into a wide variety of conventional locks. By fitting these specialty keys into a lock, and tapping it with a hammer, all of the pins inside a lock are likely to align, thereby allowing a thief to gain entry with just a small twist of the key itself. This post isn’t meant to alarm, but to inform. And on that line, it’s worth noting these facts about lock bumping:

On most conventional locks, lock bumping can be completed in about 10 seconds. It’s also a very easy technique to learn and perform, requiring virtually no special skill set.

About 90 percent of households in America have entry doors equipped with a lock that can be bumped.

It’s a non-destructive lock picking method, meaning that there’s likely to be no sign of forced entry. This can be a big issue with insurance companies, as many often require some sign of forced entry to approve claims.

Bump keys can be fabricated by anyone in minutes. And they cost just a few dollars to create, $20 tops.

Can My Locks be Bumped?

Is your home or office vulnerable to lock bumping? Consider the following:

Are your locks of the pin tumbler or cylinder variety? That’s the first big warning sign.

Did you purchase your door locks from a big box hardware store? If you answered “yes,” these locks are more than likely vulnerable, as it’s estimated that about 95 percent of the locks sold at such outlets – locks that are mass produced – are able to be bumped.

Are your locks fairly new? It’s said that newer pin tumbler locks and cylinder locks are even more vulnerable to bumping than older models.

Preventing Lock Bumping

If your home has locks that are subject to being bumped, the good news is that there are several actions you can take to prevent this. For starters, a bevy of reputable lock manufacturers are now crafting bump-proof or bump-resistant locks. These often come with a “UL 437” rating and the locks themselves usually include a small, specialty marking (i.e. a small line or criss cross) near the keyhole. Whenever there’s a will, there’s a way, so certainly we suppose a thief could still manipulate these types of locks to gain access, but generally speaking it will be much, much more difficult to do so, whether it is via lock bumping or some other lock picking method.

A more low-cost way of fending off lock bumpers is to install a chain latch to the entry door. Doing this doesn’t actually prevent lock bumping, as a thief would still be able to accomplish that, but it does add one more line of defense in terms of a crook being able to enter the home.

Some other preventative tactics include:

Having a dog: While lock bumping is fast and easy to perform, it is a process that makes noise. If a burglar hears a dog barking from the other side of the door after the bump key is hit with the hammer, they’re less likely to proceed.

Well-manicured yard: Keeping your yard in shape likely ensures that thieves have fewer areas to hide when they’re attempting to gain access to your home. Lock bumping can be done quickly, but burglars are less likely to attempt to access your home if they can’t stay inconspicuous en route.

Security system: No matter what type of lock you have, if a burglar wants it bad enough, they will break in to your home. That’s where a good security system can help, as this last line of defense can sound for the authorities if your home has been illegally accessed.

Lastly, perhaps the best way to prevent lock bumping is to have a professional locksmith analyze your situation and, if necessary, install high-security locks that cannot be bumped or easily manipulated at your home or office’s points of entry. Here at Great Valley Lockshop, we specialize in this, as we’ve been to countless homes and offices that have either been the victim of lock bumping or could very easily be accessed via the technique. Hence, the best way to prevent lock bumping is to proactively address any potential problems – and that’s where we can help.

For more information on lock bumping and how to safeguard your home or office from this burglary tactic, contact Great Valley Lockshop today by calling 610-644-5334″.

Written byChris Strauss

Chris is a Locksmith by trade and the owner of Great Valley Lockshop in Malvern PA. Chris is a volunteer firefighter and "Life Member" for East Whiteland Township Volunteer Fire Company and a huge Nascar fan who loves to go camping and enjoys the outdoors.